All you need to know about Geosynthetics, its types, uses etc. their uses in retaining walls have been focused... The Best Presentation you can possibly find on Geosynthetics.

2. Geosynthetics are materials made from various types of
polymers , used with geological materials like soil, rock etc.
to enhance, improve or modify the behaviour of various
civil engineering works.
Geosynthetics are available in a wide range of
forms and materials, each to suit a slightly different use.
These products have a wide range of applications and are
currently used in many geotechnical, transportation,
hydraulic, and private development applications including
roads, airfields, embankments ,retaining structures,
reservoirs, canals, dams, erosion control, sediment control,
landfillliners, landfill covers, mining, and agriculture.

3. 1 Geotextiles
2 Geogrids
3 Geonets
4 Geomembranes
5 Geosynthetic clay liner
6 Geocells
7 Geofoam
8 Geocomposites

4. Geotextiles are permeable fabrics
which when used in association
with soil, have the ability to separate,
filter, reinforce, protect, or drain.
Characteristics-
Porous and allow flow of water through it.
Most used Geosynthetics.
Available in rolls of 5.6m wide and 50-
150m long.

5.  Uniform and regular interweaving of
threads or yarns in two directions.
 Regular Visible Construction Pattern.
 Function: Soil Separation,
Reinforcement, Load distribution,
Filtration, Drainage
 Have high tensile strength and
relatively low strain.

6. Formed by heat bonding, resin
bonding or needle punching.
No visible thread pattern.
Function: Soil separation,
stabilization, load distribution, but not
used for reinforcement.
They have high strain and stretch
considerably under load.

7. A Geogrid is geosynthetic material used to reinforce soils and
similar materials. Geogrids are commonly used to
reinforce retaining walls, as well as sub bases or subsoil's
below roads or structures.
They have open grid like
configuration i.e. they have large
aperture between individual ribs.
They have Low strain and stretch
about 2% under load.
Strength is more that other
common geotextiles.
Function: Used exclusively for
reinforcement

8. Uneven distribution
Of load causes
wear & tear
of Roads
Load is distributed
Evenly After the
use of Geogrid
The Pathway deforms
after a certain
period of time
Geogrid used beneath the Road surface

11. A geonet is a geosynthetic material consisting of
integrally connected parallel sets of ribs overlying similar
sets at various angles for in-plane drainage of liquids or
gases.
 Geonets are made of stacked,
criss-crossing polymer strands that
provide in-plane drainage.
 Two layers of strands are called
“bi-planar”.
 Three layers are called “tri-planar”.

12. Bi-Planar
Tri-Planar

13. A Geomembrane is very low permeability synthetic
membrane barrier used to control fluid or gas migration in a
structure, or system.
Characteristics-
Impermeable and usually
non-woven,
Used as a fluid barrier in
designing drainage systems,
etc.
Used as damp proof
course in floors, roofs etc.

15. It is a woven fabric-like material, combination of geotextiles
and geomembranes used as a barrier for liquid or solid waste
containment. primarily used for the lining of landfills.
GCLs are manufactured by
sandwiching the bentonite
within or layering it on
geotextiles and
geomembranes , bonding
the layers with needling,
stitching or chemical
adhesives. Primarily used
for the lining of landfills.

16. Geocells are 3-dimensional honeycomb-like structures, made
of strips of polymer sheet.
Characteristics-
Similar to geotextiles or
geogrids but have depth.
provides both a physical
containment of a depth of soil and a
transfer of load through
Allow water through it.
Used in slopes with soft sub-grade
Used in erosion control in channels

18. Geofoam is manufactured into large lightweight blocks by
polymeric expansion process. They are large but extremely
light materials with gas filled cells.
Low density/ high strength: Geofoam is
1% to 2% the density of soil with equal
strength.
Quick to install and can be installed
during any type of weather.
 If geofoam comes in contact with
a petroleum solvent, it will immediately
turn into a glue-type substance, making
it unable to support any load.
Untreated geofoam is a Fire hazard

19. Uses-
within soil embankments built over soft, weak soils;
under roads, airfield pavements and railway track systems subject to
excessive freeze-thaw conditions.
thermal insulation in storage tanks containing cold liquids.
separation, lightweight fill, compressible inclusions,

20. These are products manufactured by combining the superior
features of various types of geosynthetics.
This is prepared to extract all the major
properties of the geosynthetics into a single unit with
minimum cost.
The various types of Geocomposites
are :-
Geotextile-Geonet Composites
Geotextile –Geomembrane
Composites
Geotextile –Geogrid Composites
Geomembrane –Geogrid Composite
Geotextile-Polymer Core Composite

21. Types Of
Geosynthetics
Separation
Re-inforcement
Filtration Drainage Containment
Geotextile YES YES YES YES
Geogrid YES
Geonet YES
Geomembrane YES
G. Clay Liners YES
Geocells YES YES
Geofoam YES
Geocomposites YES YES YES YES YES

22. Retaining walls are structures designed to restrain soil to
unnatural slopes.

23. For heavy loads or for greater slopes, concrete walls are
placed along with the use of geosynthetic.

24. If Geocells are used then even for steeper slopes, steel
reinforcements are not necceray

25. For less loads or gentler slopes only layers of geogrid with steel
reinforcement is used.